The temporal structure of acoustic signals, including human speech, plays an important role in communication. The goal of this research is to determine how temporal features of acoustic signals are integrated and processed in the central auditory system to modulate activity of reproductive neuroendocrine regions of the brain. Acoustic signals can act as important regulators of reproductive behavior. For example, acoustic courtship signals have been shown to play an integral role in coordinating mating behavior among members of same species. Such behavioral effects are often mediated by gonadal steroids whose production can be modulated by acoustic activation of hypothalamic neuroendocrine cells. The proposed research will focus on the auditory system of anurans because of the well established role that vocal signals play in reproduction for this group. The central processing of auditory information in anurans is likely to be directly relevant to many other vertebrate species as well, including humans, given that the central auditory pathways among vertebrates are largely conserved in their overall structural organization and numerous functional homologies have been identified in the central auditory pathways. [unreadable] [unreadable] [unreadable]